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Recently, inclusion complexes formed from cyclodextrins (CDs) and surfactants have been found to play complex and important roles in supramolecular self-assembly. In this work, the self-assembly of perfluorononanoic acid (PFNA)/γ-cyclodextrin (γ-CD) in aqueous solution was investigated. The sole PFNA solution assembled into spherical uni-lamellar vesicles under certain concentrations as revealed by freeze-fracture transmission electron microscopy (FF-TEM) images. Interestingly, when γ-CD was added into the PFNA solution, one novel kind of cyclodextrin-based hydrogel with a crystal-like structure was obtained. The morphology of the hydrogels was inerratic parallel hexahedron or regular hexahedron as revealed by optical microscopy and scanning electron microscopy (SEM) measurements. Furthermore, the hydrogels were transformed into crystalline precipitates, which were composed of highly uniform tetragonal sheets with excellent crystallinity and homogeneous size distribution just by changing the γ-CD concentration. More amazingly, the crystal-like hydrogels were sensitive to shear and switched to solutions in their morphology with bar-like and rod-like aggregates and smaller square sheets under different shear rates, and the hydrogel-solution transition behavior was a reversable process. 1H NMR, Fourier transform infrared (FT-IR) and wide-angle X-ray diffraction (WXRD) measurements were performed to lead us to propose the formation mechanism of the above aggregates. Hopefully, our studies will cast new light on the fundamental investigations into the self-assembly of supramolecular systems of fluorinated surfactants and CD molecules and provide a new idea for smart material design.
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OBJECTIVES: Knee osteoarthritis (KOA) is a common degenerative joint disease with no satisfactory intervention. Recently, both physical and mindfulness exercises have received considerable attention for their implications in KOA pain management, and the dorsolateral prefrontal cortex (DLPFC) has displayed a critical role in pain modulation. This study aimed to comparatively investigate the modulation effects of different exercises using multidisciplinary measurements. METHODS: 140 KOA patients were randomized into Tai Chi, Baduanjin, stationary cycling, or health education control groups for 12â¯weeks. Knee Injury and Osteoarthritis Outcome Score (KOOS), resting state functional magnetic resonance imaging (fMRI), structural MRI, and serum biomarkers were measured at baseline and at the end of the study. RESULTS: We found: 1) increased KOOS pain subscores (pain reduction) and serum programmed cell death protein 1 (PD-1) levels in the three exercise groups compared to the control group; 2) decreased resting state functional connectivity (rsFC) of the DLPFC-supplementary motor area (SMA) and increased rsFC between the DLPFC and anterior cingulate cortex in all exercise groups compared to the control group; 3) significant associations between DLPFC-SMA rsFC with KOOS pain subscores and serum PD-1 levels at baseline; 4) significantly increased grey matter volume in the SMA in the Tai Chi and stationary cycling groups, and a trend toward significant increase in the Baduanjin group compared to the control group; 5) significant DLPFC rsFC differences among different exercise groups; and 6) that baseline DLPFC-SMA rsFC can predict the effect of mind-body exercise on pain improvement in KOA. CONCLUSION: Our results suggest that different exercises can modulate both common and unique DLPFC (cognitive control) pathways, and altered DLPFC-SMA rsFC is associated with serum biomarker levels. Our findings also highlight the potentials of neuroimaging biomarkers in predicting the therapeutic effect of mind-body exercises on KOA pain.
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Terapia por Ejercicio/métodos , Osteoartritis de la Rodilla/terapia , Corteza Prefrontal/metabolismo , Adulto , Anciano , Encéfalo/fisiopatología , Ejercicio Físico/psicología , Femenino , Giro del Cíngulo/fisiopatología , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Atención Plena/métodos , Vías Nerviosas/fisiopatología , Osteoartritis de la Rodilla/fisiopatología , Dolor/fisiopatología , DescansoRESUMEN
PURPOSE: The objectives of the study were to establish a dose-response model for warfarin based on the relationship between daily warfarin dose and international normalized ratio (INR) and to evaluate the stability and reliability of the established model using external data. METHODS: Clinical data were recorded from 676 outpatients with a steady-state warfarin dosage. Demographic characteristics, concomitant medications, daily dosage of warfarin, CYP2C9 and VKORC1 genotypes, and INR were recorded. Data analysis based on the Michaelis-Menten equation to describe the relationship between daily warfarin dose and INR was performed using NONMEM. The reliability and stability of the final model were evaluated using goodness-of-fit plots, resampling techniques with a nonparametric bootstrap, and external data. RESULTS: The daily warfarin dose and INR were described by a more pharmacologically expressive model than multivariate linear regression (MLR) model. The population standard value of Km was 3.56 mg, and the Hill coefficient was 0.512, with individual variabilities of 53.1% and 55.9%, respectively. CYP2C9 *1/*3, VKORC1 AA, concomitant amiodarone, and nonheart valve replacement reduced the warfarin Km by 30.4%, 74.3%, 34.5%, and 39.4%, respectively. The Km value decreased with age and increased with fat free mass (FFM). INR prediction error (73.0%) of the external datasets was within ± 20%. CONCLUSION: A dose-response model of warfarin was established based on the relationship between daily warfarin dose and INR. Expected genotype effects on Km and demographic characteristics were confirmed. The model has the potential to be a powerful tool for individualized warfarin therapy for Chinese outpatients.
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Anticoagulantes/administración & dosificación , Relación Normalizada Internacional , Modelos Biológicos , Warfarina/administración & dosificación , Adulto , Anciano , Anciano de 80 o más Años , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
BACKGROUND: Knee osteoarthritis is a prevalent disorder with unsatisfactory treatment options. Both physical and mindful exercises may be able to relieve its pain symptoms. We compared the modulatory effects of different exercise modalities on the periaqueductal grey (PAG) and ventral tegmental area (VTA), which play important roles in descending opioidergic pathways and reward/motivation systems in patients with knee osteoarthritis. METHODS: We recruited and randomised 140 patients into Tai Chi, Baduanjin, stationary cycling, and health education control groups for 12 weeks. Knee injury and Osteoarthritis Outcome Score (KOOS), functional and structural MRI, and blood biomarkers were measured at the beginning and end of the experiment. We used the PAG and VTA as seeds in resting-state functional connectivity (rsFC) analysis. RESULTS: Compared with the control group: (i) all exercises significantly increased KOOS pain sub-scores (pain reduction) and serum programmed death 1 (PD-1) concentrations; (ii) all exercises decreased right PAG rsFC with the medial orbital prefrontal cortex, and the decreased rsFC was associated with improvements in knee pain; and (iii) grey matter volume in the medial orbital prefrontal cortex was significantly increased in all exercise groups. There was also significantly decreased rsFC between the left VTA and the medial orbital prefrontal cortex in the Tai Chi and Baduanjin groups. CONCLUSIONS: Exercise can simultaneously modulate the rsFC of the descending opioidergic pathway and reward/motivation system and blood inflammation markers. Elucidating the shared and unique mechanisms of different exercise modalities may facilitate the development of exercise-based interventions for chronic pain. CLINICAL TRIAL REGISTRATION: ChiCTR-IOR-16009308.
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Terapia por Ejercicio/métodos , Imagen por Resonancia Magnética/métodos , Osteoartritis de la Rodilla/fisiopatología , Sustancia Gris Periacueductal/fisiología , Área Tegmental Ventral/fisiología , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Vías Nerviosas/fisiología , Sustancia Gris Periacueductal/diagnóstico por imagen , Área Tegmental Ventral/diagnóstico por imagen , Área Tegmental Ventral/fisiopatologíaRESUMEN
The effects of alkyl chain length of anionic fluorinated fatty acid surfactants, CnF2n+1COOH (n = 7-11), mixed with one cationic hydrocarbon surfactant, tetradecyltrimethylammonium hydroxide (TTAOH), on the formation of polyhedral vesicle gels were investigated in aqueous solutions. On the basis of phase behavior mapping, C8F17COOH, C9F19COOH, C10F21COOH and C11F23COOH except C7F15COOH all formed polyhedral vesicle gels when they were mixed with TTAOH under certain mixed ratios, which was demonstrated by freeze-fracture transmission electron microscopy (FF-TEM) measurements. Meanwhile, the following observation was not observed: the longer the fluorinated alkyl chain, the more effective the formation of gels by fluorinated fatty acids. The formation of the faceted vesicle gels was determined both by the rigidity of the fluorinated alkyl chain and the co-crystallization of fluorocarbon chains and hydrocarbon chains, as revealed by the results of differential scanning calorimetry (DSC), wide angle X-ray scattering (WAXS) and 19F NMR measurements. Furthermore, the polyhedral vesicle gels showed high viscoelasticity, which increased clearly with increasing fluorinated alkyl chain length, indicating that the viscoelastic property of the polyhedral vesicle gel was a result of the crystalline state of the polyhedral vesicle bilayers at room temperature. As far as we know, such polyhedral vesicle gels formed from perfluorinated and hydrocarbon surfactant mixtures have been rarely reported. Our study can be a great advancement in fundamental research of surfactant vesicle gels.
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The aggregation behavior and rheological properties of two mixtures of perfluorononanoic acid (PFNA)/NaOH and perfluorodecanoic acid (PFDA)/NaOH were investigated in aqueous solutions. Interestingly, pH-sensitive polyhedral fatty acid vesicles were spontaneously formed in both systems, which were determined by freeze-fracture transmission electron microscopy (FF-TEM) measurements. Especially, a phase transition from faceted vesicles to the L3 phase with the increase of pH was observed in the PFNA/NaOH system while it was not observed in the PFDA/NaOH system. Differential scanning calorimetry (DSC) and wide angle X-ray scattering (WAXS) measurements confirmed that the bilayers of the faceted vesicles were in the crystalline station indicating that the crystallization of fluorocarbon chains was the main driving force for their formation. Besides, the two systems of faceted perfluorofatty acid vesicles exhibit interesting rheological properties, for instance, they showed high viscoelasticity and shear-thinning behaviour, and the elastic modulus (G') and viscous modulus (G'') of PFDA/NaOH vesicles were much higher than those of PFNA/NaOH vesicles. Conversely, the solution of the L3 phase with fluid bilayers did not present viscoelastic properties. Therefore, the viscoelastic properties of vesicles resulted from the crystalline fluorinated alkyl chains with high rigidity at room temperature and the dense packing of vesicles. As far as we know, such faceted fatty acid vesicles formed from single-tailed perfluorinated surfactants have been rarely reported. Our work successfully constructs polyhedral fatty acid vesicles and proposes their formation mechanism, which should be a great advance in the fundamental research of fatty acid vesicles.
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Ácidos Decanoicos/química , Fluorocarburos/química , Membranas Artificiales , Reología , Tensoactivos/química , Rastreo Diferencial de Calorimetría , Cristalización , Módulo de Elasticidad , Ácidos Grasos , Concentración de Iones de Hidrógeno , Microscopía Electrónica de Transmisión , ViscosidadRESUMEN
Background/Objective: To investigate the modulatory effects of different physical exercise modalities on connectivity of amygdala subregions and its association with pain symptoms in patients with knee osteoarthritis (KOA). Methods: 140 patients with KOA were randomly allocated either to the Tai Chi, Baduanjin, Stationary cycling, or health education group and conducted a 12 week-long intervention in one of the four groups. The behavioral, magnetic resonance imaging (MRI), and blood data were collected at baseline and the end of the study. Results: Compared to the control group, all physical exercise modalities lead to significant increases in Knee Injury and Osteoarthritis Outcome Score (KOOS) pain score (pain relief) and serum Programmed Death-1 (PD-1) levels. Additionally, all physical exercise modalities resulted in decreased resting state functional connectivity (rsFC) of the basolateral amygdala (BA)-temporal pole and BA-medial prefrontal cortex (mPFC). The overlapping BA-temporal pole rsFC observed in both Tai Chi and Baduanjin groups was significantly associated with pain relief, while the BA-mPFC rsFC was significantly associated with PD-1 levels. In addition, we found increased fractional anisotropy (FA) values, a measurement of water diffusion anisotropy of tissue that responded to changes in brain microstructure, within the mind-body exercise groups' BA-temporal pole pathway. The average FA value of this pathway was positively correlated with KOOS pain score at baseline across all subjects. Conclusions: Our findings suggest that physical exercise has the potential to modulate both functional and anatomical connectivity of the amygdala subregions, indicating a possible shared pathway for various physical exercise modalities.
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Crude oil spills have caused catastrophic damage to marine ecosystems and become a global challenge. Although various liquid absorption materials have been developed, manual operations such as pumping and electric heating are still required in the face of highly viscous spilled oils. Efficient and autonomous crude oil spill cleanup methods are urgently needed. Here, inspired by the unidirectional microstructure of tree xylem, we report a sponge (SPC-Sponge), which combines superhydrophobic property and aligned porous structures, prepared from a ternary suspension (hydrophobic silica nanoparticles, polyurethane, and cellulose nanofibers) by single-step directional freeze casting. SPC-Sponge not only effectively overcome the limitations of traditional synthetic modification methods on the shape and size of porous sponge materials, but also has excellent oil-water selection function, liquid absorption speed, and liquid absorption capacity compared with common porous materials. Moreover, the sponge can self-absorb highly viscous crude oil of around 80,000 mPaâ§s on seawater without external energy and human intervention. By adding multi-walled carbon nanotubes, the sponge can implement in-situ solar heating of crude oil, and the absorption speed is further improved. Given its unique structural design and superwetting property, this SPC-Sponge provides an efficient remediation approach for viscous oil spills.
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Nanotubos de Carbono , Petróleo , Ecosistema , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Aceites/química , PorosidadRESUMEN
Efficient micron-sized droplet separation materials have become a new demand for environmental protection and economic development. However, existing separation methods are difficult to be effectively used for micron-sized water droplets surrounded by viscous oil, and common materials have difficulty maintaining hydrophilicity underoil. Here, inspired by the microstructure of tree xylem, we report a cellulose-polyurethane sponge (CP-Sponge) with wood-like pores and underoil superhydrophilicity using directional freeze-casting. The CP-Sponge has an excellent selective water absorption capacity underoil and compression resilience. This preparation strategy can flexibly control the sponge's dimensional morphology. The designed cylindrical CP-Sponge can be easily installed in the silicone tube of a peristaltic pump. During pump operation, with a simple absorption, compression, and recovery process, the CP-Sponge continuously and effectively removes micron-sized water from crude oil and lubricating oil, reducing residual water in the oil to less than 2 ppm. The absorption-saturated sponge can be dried to continue recycling. Eco-friendly, recyclable, and sustainable artificial porous sponges provide new ideas and inspiration for the practical application of deep dehydration of viscous oils.
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HYPOTHESIS: Amphiphilic Janus nanosheets are plate-shaped, with one hydrophilic and one hydrophobic side; they are expected to assemble at oil-water interfaces. The assembled Janus nanosheets layers at the oil-water interface will exhibit a unique mechanical response under the vertical pressure of a probe. EXPERIMENTS: The interfacial behaviors of amphiphilic Janus nanosheets and the morphology of the assembled particle film at an oil-water interface were observed. The dynamic morphologies and force-displacement curves of the oil-water interface covered with amphiphilic Janus nanosheets were investigated during the insertion of a cylindrical probe. FINDINGS: Amphiphilic Janus nanosheets spontaneously aggregated at the oil-water interface. The morphology of the assembled particle film was controlled by the interfacial nanosheets concentration and can be divided into three regimes: unsaturated, monolayer, and collapsed. The wettability of the probe and the density of nanosheets at the interface played critical roles in the deformation and mechanical response of the oil-water interface under vertical pressure. The presence of amphiphilic Janus nanosheets reduced the stiffness and enhanced the flexibility and deformability of the oil-water interface. The oil-water interface covered with amphiphilic Janus nanosheets could produce larger deformation under a smaller vertical stress. This work not only improves the understanding of the interfacial properties of amphiphilic Janus nanosheets but also provides a method for characterizing nanoparticle layers at oil-water interfaces.
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Premature water production is an inevitable issue that results in loss of quantities of reserves in heterogeneous oilfields especially with large permeability ratios. Hydrogel treatments, preferentially plugging large channels, are efficient techniques to reduce excessive water circulation. In this work, a moderate delayed polyacrylamide hydrogel was fabricated applying in-depth plugging to promote oil production. Suitability tests of delayed hydrogel in the presence of quartz sand confirmed its mature delay over 10 days, providing the low-viscosity gelant sufficient time for entering the deep layer. Single sand-pack displacement tests demonstrated the excellent plugging ability in differential permeability layers to strongly promote the follow-up oil production. Aiming at heterogeneous reservoirs with three different permeability ratios, conventional displacements and hydrogel treatments were sequentially conducted. In comparison with water- and polymer-flooding that mainly performed exploitation at low-permeability-contrast layers (K high/K low = 3), the delayed hydrogel technique after polymer-flooding was capable of improving the oil recovery efficiency of unswept zones at high-permeability-contrast zones (K high/K low ≥ 10). Recovery in heterogeneous layers with permeability ratios (K high/K low) of 10 and 15 was enhanced to 48 and 59%, respectively from 18 and 0%. In addition, rheological behaviors and morphologies elucidated the delayed hydrogel with extruding deformation and high yield strength, facilitating water shutoff and improvement of oil production.
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To study the microscopic dispersion state of CO2 in different ester solvents, the solubility, volume expansion coefficients and in situ Fourier transform infrared (FTIR) spectra of the CO2-ester system were measured. The results show that the solubility and expansion coefficient of CO2 in ester solvents decreases as the hydrocarbon chain increases. As the pressure increases, the infrared absorption peaks of CO2 and the functional groups characteristic of ester molecules shift, indicating that CO2 molecules interact with ester molecules and that CO2 would destroy the interactions between the ester molecules. The hydrocarbon chain length of the ester molecules has a significant effect on the infrared absorption peak of the CO2-ester system. As the hydrocarbon chain length increases, the CO2 absorption peak shift and peak shift of the carbonyl groups in the ester gradually decrease.
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HYPOTHESIS: Imidazolium-based Ionic liquids as new generation cationic surfactants can provide designable alkyl chain length. In the catanionic surfactant systems, the alkyl chain lengths and molar ratios can greatly influence the interactions such as electrostatic and hydrophobic interaction. The variation in these interactions has a significant effect on the molecular environments of the self-assembly structure, and this process is always accompanied by the transition of aggregates and release or consumption of heat. Hence, it is of interest to study the relationship between intermolecular interactions, molecular environments, self-assembly structure and the change in energy of system in the catanionic surfactant mixed systems. EXPERIMENTS: The enthalpy change ΔH of titrations the imidazolium-based into SDS micelle solution was studied to characterize the heat by using isothermal titration calorimetry (ITC) during the transitions of the aggregate structures. The corresponding self-assembly structure was monitored via cryogenic transmission electron microscopy (cryo-TEM). Employing proton magnetic resonance (1H NMR), we focus on the interactions between imidazolium-based ILs and SDS based on the variations in the molecular environments of aggregates. FINDINGS: Of these imidazolium-based ionic liquids/SDS system, the 1-octyl-3-methylimidazolium ([OMIM]Cl)/SDS system shows several features such as intense energy absorption and releasing processes, which indicate the formation of high entanglement wormlike micelles and vesicles. This is related to the formation of self-adjusting state between the SDS and [OMIM]Cl molecules due to the balance between the electrostatic interaction and hydrophobic interaction. Varying the alkyl chain length appears to cause significant differences to the molecular environments. From the molecular environments, three different models about the polarity of the catanionic surfactant molecules are used to explain the balance of the intermolecular interactions.
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In order to obtain polymer microspheres for profile control and water shutoff with high temperature resistance and good swelling properties, micrometer microspheres with a double crosslinked structure were synthesized using the monomers acrylamide (AM), N-vinylpyrrolidone (NVP) and 2-acrylamide-2-methylpropanesulfonic acid (AMPS), an initiator of potassium persulfate, a crosslinking agent of N,N-methylene bis acrylamide and zirconium acetate. The crosslinked Zr-AM/NVP/AMPS microspheres were fully characterized with several means including FT-IR, 13C NMR, TG-DSC and SEM. Metal crosslinking was introduced into the polymer microspheres to improve the temperature resistance by crosslinking the hydrolyzed polymer molecular chains. The results of optical microscopy and scanning electron microscopy demonstrated that a double crosslinked structure (DCS) was formed inside the Zr-AM/NVP/AMPS microspheres. It is regrettable that there is no three-dimensional network structure in the microspheres with single organic crosslinked structure (SCS). In aqueous solution, the DCS polymer microspheres were able to maintain long-term thermal stability for 150 days even at a high temperature of 140 °C. The microspheres with SCS can only be preserved for 5 days in high temperature aqueous solution at 140 °C. The TGA-DSC results indicated that the aerobic temperature capability of the DCS microspheres has been greatly improved compared with HPAM and SCS microspheres. The DCS microspheres with ultra-high temperature resistance will have broad application prospects in high temperature reservoirs.
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Polymerizable microspheres are introduced into acrylamide to prepare the high mechanical strength hydrogels with a novel three-dimensional pore structure. Rheological properties, compressive stressâ»strain, tensile property, and compression strength of three different types of hydrogels were investigated. Moreover, a scanning electron microscope (SEM) was adopted to observe the three-dimension network structure of three different types of hydrogels. The test results illustrated that viscous moduli (Gâ³) and elastic moduli (G') of a hydrogel containing polymerizable microspheres (P) reached maximum values, compared to the normal hydrogel (N) and the composite hydrogel containing ordinary microspheres (O). When the hydrogels were squeezed, the N was easily fractured under high strain (99%), whereas the P was not broken, and quickly recovered its initial morphology after the release of load. The P showed excellent tensile properties, with an elongation at break up to 90% and a tensile strength greater than 220 g. The compression strength of the N was 100.44 kPa·m-1, while the resulting strength of P was enhanced to be 248.00 kPa·m-1. Therefore, the various performances of N were improved by adding polymerizable microspheres. In addition, the SEM images indicated that N has a general three-dimensional network structure; the conventional network structure did not exist in the P, which has a novel three-dimensional pore structure in the spherical projection and very dense channels, which led to the compaction of the space between the three-dimensional pore network layers and reduced the flowing of free water wrapped in the network. Therefore, the mechanical strength of hydrogel was enhanced.
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OBJECTIVE: This study aims to screen and validate five individual warfarin dosing models (four Asian model algorithms, namely, Ohno, Wen, Miao, Huang, and the algorithm of International Warfarin Pharmacogenetic Consortium, namely IWPC algorithm) with the aim of evaluating their accuracy, practicality, and safety. MATERIALS AND METHODS: Patients' CYP2C9*3 and VKORC1-1639G >A genes were genotyped, and patient-related information and steady warfarin doses were recorded. The difference between the predicted dose and actual maintenance dose of each model was compared. RESULTS: The prediction accuracies of the Huang and Wen models were the highest. In terms of clinical practicality, the Huang model rated the highest for the low-dose group, whereas the Ohno and IWPC models rated the highest for the middle-dose group. The models tended to markedly overpredict the doses in the low-dose group, especially the IWPC model. The Miao model tended to severely underpredict the doses in the middle-dose group, whereas no model exhibited severe overprediction. CONCLUSIONS: Since none of the models ranked high for all the three criteria considered, the impact of various factors should be thoroughly considered before selecting the most appropriate model for the region's population.
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Anticoagulantes/administración & dosificación , Modelos Teóricos , Farmacogenética , Warfarina/administración & dosificación , Citocromo P-450 CYP2C9/metabolismo , HumanosRESUMEN
Nano-silica was introduced to enhance the mechanical strength of polymer hydrogels obtained via the crosslinking of polyacrylamide (PAM) and chromium acetate. Rheological properties, compression strength and compressive stress-strain of both nanocomposite and normal hydrogels without nano-silica were investigated by HAKKE rheometer, compression strength test device and electronic universal material testing machine. Moreover, environmental scanning electronic microscopic (ESEM) was adopted to observe the three-dimension network structure of nanocomposite and normal hydrogel, as well as the distribution of nano-silica. The results demonstrated that elastic moduli (G') and viscous moduli (Gâ³) of nanocomposite hydrogel were both improved with increasing nano-silica concentration. Especially when silica content reached 10wt%, G' and Gâ³ of nanocomposite hydrogel increased over one hundred times higher than those of normal hydrogel. The original compression strength of hydrogel was 70.8kPam(-1), while the resulting strength of nanocomposite was enhanced to be 196.64kPam(-1). When the hydrogel were sheared, the normal hydrogel was fractured under low strain, whereas nanocomposite hydrogel was not broken under high strain, and it quickly recovered its original shape after the release of load. In addition, the ESEM images indicated that a large quantity of silica particles aggregated and attached around the polymer chains, and others aggregated to fill into the three-dimension network of hydrogel, which induced the compaction of the space between the network layers and reduced the flowing of free water wrapped in the network, therefore the mechanical strength of hydrogel was enhanced.
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The aim of this study was to establish clinical and genetic factors-based individual administration model of tacrolimus for Chinese Han patients after renal transplantation (RT). The genetic polymorphisms of CYP3A4, CYP3A5 and MDR1 in 216 RT patients were detected by PCR-RFLP, the genetic and clinical factors and blood concentration/dose × body weight (C/D) values of tacrolimus were performed the single factor correlation analysis, and established the dose prediction algorithm of tacrolimus by stepwise multiple regression analysis. CYP3A5*3, hematocrit and albumin were correlated with the C/D values of tacrolimus, the best regression model could explain 28.3% reason of individual dose differences of tacrolimus, among which CYP3A5*3 polymorphism could explain 23.5%. The genetic factors played an important role in the dose differences of tacrolimus, the patients should be checked CYP3A5*3 genotype before administration of tacrolimus to predict the tacrolimus doses, thus helping to improve the safety and effectiveness of tacrolimus application.
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Scanning electron microscopy (SEM), dynamic lighting scattering (DLS) and HAAKE rheometer experiments were adopted to investigate the shape, size and rheological properties of nanoscale polymer microspheres. Moreover, nuclear-pore film filtration, sand packed tube displacement, core displacement, micro-visual model and capillary flow experiments were used to study the mechanisms of deep profile control and oil displacement of nanoscale polymer microspheres. The results demonstrated that the original shape of the nanoscale polymer microspheres were typically spherical, ranging in size from 30 to 60 nm. When the microspheres were dispersed in water, their size increased by 3-6 times due to swelling and a poly-dispersed system appeared; however, the spherical conformation remained. Within a certain range of shear rates, a 100-900 mg/L microsphere dispersed system exhibited shear thickening behaviour, making it favourable for increasing the flow resistance of a displacement fluid. These polymer microspheres dispersed systems exhibited effective plugging on a nuclear pore film with 0.4-µm pores with deep plugging in the core; these systems also tended to plug the high permeability layer and drive crude oil from the low permeability layer in parallel sand packed tubes. Cross-linked polymer microspheres could reduce water permeability because the microspheres adsorbed, accumulated and bridged in the pore-throat, and the adsorbed layers would be collapsed under the pressure, entering deep into the reservoir due to the good deformation properties of the microspheres. Meanwhile these microspheres would drive crude oil on and in the pores/throats while they are transported in porous media, achieving deep profile control and oil displacement with the ultimate purpose of improving oil recovery.